C/C++ Sample: Acquire and save to BMP file

The following 'C' / C++ function is all that is required to do the following:

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#include <dtwain.h>

#include <tchar.h>  // for Windows _T macro to denote string type

void ExampleFunction( )  

{

   DTWAIN_SOURCE TheSource;    /* The TWAIN Data Source */

   DTWAIN_BOOL RetVal;

   LONG Status;

   /* Check if TWAIN exists.  Return if TWAIN is not installed */

   if ( DTWAIN_IsTwainAvailable( ) == 0 )

           return;

   /* Initialize DTWAIN DLL, return if there is a problem */

   if ( DTWAIN_SysInitialize( ) == 0 )

          return;

   /* Select the Twain Source */

   TheSource = DTWAIN_SelectSource( );

   /* If no Source selected or there is a problem, uninitialize DLL and return */

   if ( TheSource == NULL )

   {

          DTWAIN_SysDestroy( );

          return;

   }

  /* Proceed to acquire image and save to a bmp file */

  RetVal = DTWAIN_AcquireFile(TheSource,   /* Source */

                                                           _T("test.bmp"),   /* File name */

                                                            DTWAIN_BMP,  /* File type is BMP */

                                                            DTWAIN_USENATIVE | DTWAIN_USENAME,  /* acquisition options */

                                                            DTWAIN_PT_DEFAULT, /* use default color type */

                                                            1,           /* Acquire 1 page */

                                                            TRUE,   /* Show the device's user interface */

                                                            FALSE. /* Do not keep Source open when finished. */

                                                            &Status);  /* returned status */

   /* Close down TWAIN,  Data Sources, etc. */

  DTWAIN_SysDestroy( );

}

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The example above is a C or C++ function that demonstrates some of the power of DTWAIN.  The only functions that are DTWAIN specific are the following:

DTWAIN_IsTwainAvailable is only optional.  DTWAIN will still work correctly in a system that has no TWAIN drivers installed by returning an error if a selection of a TWAIN device is attempted.

Note that DTWAIN has the ability to save the images to a file (as in the example above shows), or if your application wants the raw image data, a "handle" to the image data can be returned instead of writing the image data to a file.

If you are using C++, you can use the traditional DTWAIN interface as the program above demonstrates, or the DTWAIN C++ class wrapper.  Here is a console program using the C++ class wrapper that essentially does the same thing as the program above:

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#include "cdtwain.h"

using namespace DTWAIN;

int main( )

{

  DTwainInterface TwainInterface;  // Initialize DTWAIN

   if ( TwainInterface.IsValid( ) )  // Check if valid interface

   {

          DTwainSource Source = DTwainSource::Select( );

           if ( Source.IsValid( ) )

      DTwainAcquirer( Source ).Acquire(_T("test.bmp") );

   }

} // shuts down TWAIN, DTWAIN automatically

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Note how much shorter using the DTWAIN class wrapper code is.  This code

This is a lot of power in just a few lines of C++ code.